#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <stdarg.h>


#define _GNU_SOURCE

/**
 * @brief 清理缓存
 */
#define CLEAR_BUF \
    {\
    int ch; \
while ((ch = getchar()) != EOF && ch != '\n')\
        {\
        ; \
        }\
    }
    
int connectPOP(void);
int login(char netid[50], char pw[20], int sock);